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143 Cards in this Set
- Front
- Back
Show the control of reflex sensory fibers and UMN's on LMN activity.
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When do the UMN exert their inhibitory effect on a reflex?
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After one reflex contraction, they inhibit the LMN's.
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The subcortical spinal tracts control which kinds of muscles?
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trunk muscles
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Can you show a pic of the corticospinal vs subcorticospinal tracts? (subcortical intitiated from cortical collaterals)
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WHat happens if you have a lesion of one side of a corticospinal vs subcortical spinal tract? Why?
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corticospinal- contralateral motor deficits
subcorticalspinal- no noticable deficits because they innervate trunk muscles bilaterally so the other side can compensate |
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Does the rubber mat or ViP only control flexor/extensors?
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No they are biased towards f/e, but they can do both.
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DO we have to consider the accessory motor pathways extensively? Why?
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No because they are poorly understood and also compensate for one another because they have bilateral innervation.
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Is the agonist muscle in a tendon stretch reflex the only muscle affected by the reflex arc? What other pathway happens?
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No, the antagonist is inhibited via inhibitory interneurons.
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Show a picture of the activating and inhibitory pathway in a muscle stretch (myotactic) reflex.
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Is there an inhibitory interneuron present in the GTO reflex? WHat is the general rule?
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Yes! Anytime you need to relax a muscle reflexively, there is an inhibitory interneuron involved.
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What is an alternate name for the GTO reflex?
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inverse muscle stretch reflex.
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NOW WE TALK ABOUT COMMONLY TESTED NEUROLOGICAL SIGNS!
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CLINICALERIFFIC!
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essentially what neurons are we trying to test for when we test a DTR?
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all UMN's above it and the LMN at that level feeding that muscle.
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Give the chart of what spinal level each DTR tests. (5)
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What nerve is being tested in the patellar reflex? Which spinal roots come out to make this giant leg nerve?
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The femoral nerve created by L2-L4
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What nerve is being tested in the achilles tendon reflex? Which muscles does it innervate?
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The posterior tibial nerve innervating the calf muscles (gastrocnemius and solieus)
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What is he scale for grading muscle strength? What is 0?
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0/5-5/5
0 is paralysis |
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Are people with UMN lesions going to have weakness? Why?
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Yes because they have lost part of their ability to tell that muscle what to do. (nevermind that it is tense and hyperreflexive on its own)
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What is he scale for grading muscle reflex? What is 0?
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0-4+
0 is no reflex |
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What kind of grade would a person with a LMN lesion vs UMN lesion get on DTR's? Normal?
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LMN- 0
UMN- 4+ Normal- 2+ |
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How would you use words to describe a DTR that is 2+?
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Normal, moderately brisk
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What is clonus?
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repeated reflex contractions after a stretch
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When does fasiculations vs atrophy come about in a severe LMN lesion?
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fasiculations- early manifestation (during anterograde LMN degeneration)
atrophy- late manifestation |
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What are the clinical terms to define the type of weakness in LMN vs UMN lesions?
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LMN- flaccid paralysis
UMN- spastic paresis (weakness) or paralysis (total loss of movement) |
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What does pathognomonic mean?
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A sign that indicates a certain disease beyond a doubt
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What is a positive babinski's sign pathognomic for?
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an UMN lesion
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What is the meaning of phyte?
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something that grows on something else
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Give a medical and ecological example of the usage of -phyte.
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osteophyte- bone grwoth
saprophyte- fungus that grows of dead or decaying matter. |
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A person is weak. Do they have UMN or LMN lesion?
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You don't know. It could be either.
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How can you find out if it is LMN or UMN?
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do a DTR test
LMN- areflexia UMN- hyperreflexia/clonus |
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Is tone and reflexivity always in the same direction?
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yes
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What happens if you have untreated carpal tunnel syndrome for a long time?
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the median nerve will degenerate and then the muscles of the hand will atrophy
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What sign happens before degeneration in a LMN lesion?
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fasiculations
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Do we know how fasiculations happen physiologically? What do they look like?
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Like a bunch of muscle twitches. (no one really knows why so Dr. Najeeb was just making a plausible explanation)
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Why does a UMN lesion usually just result in paresis rather than paralysis?
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Because there are accessory UMN's (extrapyrimidal) to help with conrol of the muscle
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Show a picture of decorticate vs decrerebate rigidity/posturing.
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What kind of subcortical collateral lesion would result in decorticate or decerebate posturing? WHy?
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the one to the red nucleus because this controls wrist muscles for support.
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What determines if a pt with a UMN lesions will have paresis or paralysis?
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the extent of the damage
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TIME TO TALK ABOUT THE CEREBELLUM
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lovely
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What is the main 3 functions of the cerebellum?
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1. To promote the smooth execution of muscle movements (fine tuning)
2. To plan muscle movements 3. Motor learning |
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What does it prevent?
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1. Fine tuning function- jerky movements
2. Planning- something else (can't think of it) |
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How does the cerebellum do these things on a general level?
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by comparing the intended movement (corticopontine) with the actual movement (spinocerebellar)
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Show the vermis and how deep down the cerebellum it goes.
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not just the cortex!
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What muscles does the vermis vs paravermis/intermediate hemisphere control?
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vermis- axial and proximal limb movements
paravermis- distal limb movements |
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What does the "lateral hemisphere" control? WHy does it's location next to the intermediate hemisphere make sense then>
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motor planning
distal limbs need the most amount of motor planning |
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Show the flocculonodular lobe?
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What region of there cerebellum (vermis etc) is it a part of?
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It is a little bit of all of them depending on the zone.
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Which part of the floccolonodular lobe looked the biggest?
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The vermis part
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So what can you infer about it's function from that?
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it is important for control of trunk muscles
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What are trunk muscles mainly used for?
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Posture and balance
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What is another name for the flocculonodular lopbe?
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The archicerebellum
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What structure does the flocculonodular lobe get it's input from?
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The vestibular nuclei
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So What are it's two functions?
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1. Help body stand up (ViP) and balance
2. Regulate MLF for eye movement |
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Which region of the cerebellum will send out fibers to the extrapyrimidal tracts the most?
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The vermis/flocculonodular lobe
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What is the only type of neuron to exit the cerebellum?
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purkinjie cells
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What are the most giant cells in the cerebellum?
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the purkinjie cells
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What NT does the purkinjie cells only use? Implications?
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GABA. All output of the cerebellum is inhibitory
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What is the only type of input going into the cerebellum?
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mossy and climbing fibers which are both excitatory
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What do all purkinjie cells end at?
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deep cerebellar nuclei, which means they carry out all the effective cerebellar output
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What will the deep cerebellar nuclei neurons end on?
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always UMN's (main and supporting)
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What is the main function of the mossy fibers?
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To update the cerbellum about ongoing movements or motor plans
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What is the main function of the climbing fibers?
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They update the cerebellum about errors in movment
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What would you not have if you had damage to your inferior olive or the climbing fibers?
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You would not be able to have motor learning
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Name whihc fibers fufill the following functions.
Tell cerebellum about... 1. The motor plan 2. The motor outcome 3. Help with motor leanring |
1. plan- corticopontine
2. outcome- spinocerebellar 3. learning- inferior olive/climbing fibers |
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Which spinocerebellar tracts are responsible for arm vs leg movement?
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ventral- arm proprioception
dorsal- leg proprioception (the slide on his lecture was ******* wrong, textbook) |
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What is the only real thing you need to know about what comes in and out of the cerbellar peduncles?
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input comes through mainly the inferior and middle peduncles
output mainly goes through the superior |
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What are the two fissures of the cerebellujm?
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primary and posterolateral
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What is anterior and posterior in the cerebellum? (think embryology)
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up top is anterior
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Show the cerebellum and point out where the two fissures are
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Show which region of the cerebellum each deep nuclei is in. Note their size and shape too.
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Where do the do the deep cerebellar nuclei mainly send their fibers out? (peduncle) exception?
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the superior peduncle except the vermis/flocculonodular lobe goes through the inferior
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What is the general rule for what must pass through the thalamus?
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Any fiber, sensory or motor, must pass through the thalamus if they want to REACH THE CORTEX
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Judging from their functions, the fibers from which deep nuclei go to the red nucleus vs the corrtex?
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red nucleus- paravermal- eboloform and globus
cortex- dentate |
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So which part of the thalamus will relay the denate nuclei fibers?
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the ventral anterior and ventral lateral
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Do the cerebellar cortical fibers cross? Where?
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Yes, in the midbrain
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What side of the cortex will the right cerebellum plan and fine tune for? What side of the body is this?
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the left of the cortex
the right of the body |
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Show how the fibers cross back and forth in a frontal view.. Note which level they cross at.
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What sx will a person with cerebellar disease have? Will they have weakness?
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tremor WITH MOVEMENT (intention tremor)
no weakness |
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Which side will a pt tend to fall with a cerbellar lesion?
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the side ipsilateral to the lesion
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What kind of sx will a person will a pt with a vermal lesion have? Why?
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an ataxic gait becase they cannot use their thigh muscles well
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Dissect a-taxic gait.
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a- not
taxic- ordered disordered gait |
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How will a person with an ataxic gait walk? Why?
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With their feet very far apart because they are probably scared of falling
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What kind of ataxia is this when you have a cerebellar lesion?
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a MOTOR ataxia
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Under what conditions will a person with motor ataxia lose their balance?
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under all conditions
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do you have tremors with cerebellar lesions at rest?
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no, only with movement
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When do these intention tremors increase? Why?
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As you are nearing the object because that requires the most fine tuning which you don't have.
Since it is motor, looking won't help it much. |
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What other two intention tremor disorders may people with cerebellar lesions have?
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dysmetria and dysdiachokinesis
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What is the classic test for dysmetria?
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finger to nose
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How many times do you need to test finger to nose?
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Twice, once on each side.
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What are the only two NT's used in the cerebellum?
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GABA and glutamate
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WHat two sx would someone with a flocculonodular lobe dysfunction have?
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scanning speech (scanning dysarthria)
and abnormal conjugate gaze |
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What is scanning speech like?
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you isolate each syllable you say so it sounds really chopped up.
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dissect dys-arthria
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dys- bad
arthria- articulation |
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What blood thing will damage purkinjie cells in the short vs long term?
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short- alcohol excess
long- thiamine deficiency |
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What particular part of the cerebellum purkinjie are affected? Mnemonic?
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the vermal purkinjie cells because they are involved with balance and officers use the straight line test
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NOW WE TALK ABOUT THE BASAL GANGLIA
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WOOT
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What is the main job of the basal ganglia?
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To get movements started
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How do the basal ganlia and cerebellum work together?
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CB helps plan the movement
the BG gets the movement started and the Cb makes sure it is run smoothly |
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What regions of the basal ganglia are subtelecephalic (4), diencephalon (1), and brainstem (1)?
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subtelencephalic- CN, putamen, GPI, GPE
diencephalic- subthalamus brainstem- SN |
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Is subtelencephalic part of the telencephalon?
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yes
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WHat is the destination of the BG?
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UMN in the cortex
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WHat 4 NT's are used by the BG?
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GABA, Glutamate,
ACh, dopamine |
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Show a netters diagram of what the internal capsule looks like.
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What passes through the internal capsule?
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ALL AXONS THAT LEAVE OR ENTER THE CORTEX
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highlight where the straitum is in the last pic.
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Show a coronal view of what the internal capsule (blue) and striatum (red) look like.
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What NT's will enhance the direct vs indirect pathways?
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direct- DOPA
Indirect- ACh |
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WHat is it called to have two inhibitory neurons next to each other?
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disinhibition (the following neuron is activated)
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What things do the direct and indirect pathway have in common?
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They both start and end with an excitatory neuron
They both contain one set of disinhibitory neurons |
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Which thalamic nuclei does the BG feed fibers through?
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same as the cerebellum
VA and VL |
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What is the same about the begining couple of neurons in the direct and indirect pathways? What is different later?
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They are both
exite-inhibit-inhibit-excite The indirect has an extra alternamting inhibit-excite afterwards |
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How does the indirect pathways complement the direct?
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It inhibits all other muscle movements so you can focus on the tast at hand
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WHat is the net effect of dopamine on movement?
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promotes more movement by aiding the direct and inhibiting the indirect
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What is the MAIN effect of ACh?
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To suppress unwanted movement and help the indirect pathway. (although it has a small aiding effect on the direct as well)
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What kind of of tremors will parkinson's people have?
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tremors at rest (problems in suppressing movement)
hypokinesia |
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Basically sum up the main function of dopamine and ACh in the BG.
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Dopamine- help direct pathway intitate movements
ACh- help indirect pathway suppress movements |
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Which side of the body will be afected by a lesion of the BG on one side?
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the opposie side because the BG affects the ipsilateral cortex which innervates the contralateral body.
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What pathway is affected in Parkinson's?
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the direct pathway, which is underactive
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WHy do pt's with Parkinsons get resting tremors then?
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We're not really sure
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What is an example of a parkinson's resting tremor? WHat does it look like?
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A pill rolling tremor which looks like the pt is trying to roll a pill between their fingers
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Show a pic of the guy with pill rolling tremors
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Can parkinson's affect young people?
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YES! Juvenille onset parkinson's
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What can you see often in the dopaminergi neurons that are degenerating?
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Lewy bodies which are eosinophilic inclusions containing alpha synuclein
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What degenerates and where in Huntington's disease? Mnemonic?
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The GABA neurons contained in the head of the caudate nucleus.
(why the caudate nucleus shrinks) |
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What happens to the activity of the cortex in Huntington's vs Parkinson's?
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H- overactive
P- underactive |
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dissect the word chorea
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dance (choreography) like
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What is athetosis?
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writing limb movements
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Why don't we just give dopamine for parkinson's pts?
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because it can't cross to BBB
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Does L-DOPA fix all sx?
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No, the resting tremors are still there and we don't know where they are coming from
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WHat other drug could help people with parkinson's? WHy?
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a muscarinic blocker so block the ACh's promoting of the indirect pathway... allowing more movement
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What surgery has been shown to help with tremors?
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taking out a part of the BG
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Is L-DOPA a sustainable treatment option for Parkinson's?
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No, it wears off over time
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Wilson's disease is also known as _____ degeneration.
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hepatolenticular degeneration
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What is pathognomonic for Wilson's disease?
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a Kayser-Flischner ring (can be VERY SUBTLE)
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Will people with WIlson's have sx more like parkinson's or huntington's?
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Either one depending on which pathway gets degeneration (direct or indirect)
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what characteristic tremor will pts with wilson's get?
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wing beating tremor
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Show the boy with the wing beating tremor. Describe it?
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arms contracted slightly and beating. No movement in legs.
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What types of drugs are used to treat Wilson's?
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a copper chelator or another mineral to block absorption
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Which is the copper chelator?
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pencillamine
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which is the mineral to block absorption?
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zinc acetate
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What type of stroke causes a hemiballism? (think logically)
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It would havew to be an intracranial stroke to reach the subthalamus.
Specifically, a lacunar hemorrhagic stroke. |
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Whaty disease is this? What side of the body is affected?
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Parkinson's disease for the left side of the body
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Why is the substantia niagra black?
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It releases melanin as a byproduct of dopamine synthesis.
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